In the real world making large volumes of things appear at one specific location takes effort. The real world is also fairly good about having ways to track down and prosecute those who are unusually heinous about some activity. There are costs, resources, and attachments of presence involved.

In this context the closest example would be the PTSN (Public Telephone Switched Network). That analogy still fails because while the cost is low there is still SOME cost and a lot of documentation about who might be 'making someone's phone blow up'. However from the perspective of the solution it still holds true.

On many hard-phone-lines it is possible to dial a number sequence to block calls from the number which previously called the phone. In this case the provider hired by the victim will deny the connection request before it ever reaches the victim.

Something similar can currently happen as 'blackholing' the victim, but this is victim blaming and allows the attacker to win. What is necessary is to instead push the blocking far enough back the chain that the victim sees no bill and is completely impugned from the actions of bad actors. Logically, this means blocking it at the backbone level or lower, and still charging the sending party for the data.